/*-
 * ========================LICENSE_START=================================
 * Core
 * %%
 * Copyright (C) 2020 Smooks
 * %%
 * Licensed under the terms of the Apache License Version 2.0, or
 * the GNU Lesser General Public License version 3.0 or later.
 *
 * SPDX-License-Identifier: Apache-2.0 OR LGPL-3.0-or-later
 *
 * ======================================================================
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * ======================================================================
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 3 of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 * =========================LICENSE_END==================================
 */
package org.smooks.engine.converter;

import org.smooks.api.SmooksConfigException;

import java.text.DecimalFormat;
import java.text.NumberFormat;
import java.util.Locale;
import java.util.Properties;

/**
 * Abstract {@link Number} based DataDecoder.
 *
 * @author <a href="mailto:tom.fennelly@gmail.com">tom.fennelly@gmail.com</a>
 */
public abstract class NumberTypeConverter<S, T> extends LocaleAwareTypeConverter<S, T> {

    public static final String FORMAT = "format";
    public static final String TYPE = "type";

    protected NumberFormat numberFormat;

    private NumberType type;

    @Override
    public T convert(final S value) {
        return doConvert(value);
    }

    protected abstract T doConvert(S value);

    public enum NumberType {
        RAW,
        PERCENTAGE,
        CURRENCY
    }

    @Override
    public void setConfiguration(final Properties properties) throws SmooksConfigException {
        super.setConfiguration(properties);
        if (properties != null) {
            String pattern = properties.getProperty(FORMAT);
            String typeConfig = properties.getProperty(TYPE);
            Locale locale = getLocale();

            if (locale == null && pattern == null) {
                // Don't create a formatter if neither locale or
                // pattern are configured...
                return;
            }

            if (locale == null) {
                locale = Locale.getDefault();
            }

            if (typeConfig == null) {
                type = NumberType.RAW;
            } else {
                try {
                    type = NumberType.valueOf(typeConfig);
                } catch (Exception e) {
                    throw new SmooksConfigException("Unsupported Number type specification '" + typeConfig + "'.  Must be one of '" + NumberType.values() + "'.");
                }
            }

            if (type == NumberType.PERCENTAGE || (pattern != null && pattern.indexOf('%') != -1)) {
                type = NumberType.PERCENTAGE;
                numberFormat = NumberFormat.getPercentInstance(locale);
            } else if (type == NumberType.CURRENCY) {
                numberFormat = NumberFormat.getCurrencyInstance(locale);
            } else {
                numberFormat = NumberFormat.getInstance(locale);
                numberFormat.setGroupingUsed(false);
                if (pattern != null && numberFormat instanceof DecimalFormat) {
                    ((DecimalFormat) numberFormat).applyPattern(pattern);
                }
            }
        }
    }

    /**
     * Get the {@link NumberFormat} instance, if one exists.
     *
     * @return A clone of the {@link NumberFormat} instance, otherwise null.
     */
    public NumberFormat getNumberFormat() {
        if (numberFormat != null) {
            return (NumberFormat) numberFormat.clone();
        } else {
            return null;
        }
    }

    public NumberType getType() {
        return type;
    }

    public boolean isPercentage() {
        return type == NumberType.PERCENTAGE;
    }

}
